Can no longer boot with intel_iommu=on after this is applied. Reverting this for 4.2 (and similar for 4.6) allows booting again, and I can confirm that iommu/VT-d is still functional after this. -> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/iommu/intel-iommu.c?id=5f0a7f7614a9d99325ac8d618f1cdf7a3014287c Hardware: Gigabyte GA-X58A-UD5 (Ff1 BIOS) Probably the same issue has been reported at: https://www.redhat.com/archives/vfio-users/2016-May/msg00183.html This is with GA-EX58-UD5 and Asus Rampage II Gene hardware on kernel 4.2 and 4.4.
Can you please post dmesg right after boot with a kernel that has 5f0a7f7614a9d99325ac8d618f1cdf7a3014287c reverted?
Created attachment 220181 [details] 4.6.2 dmesg with 5f0a7f7614a9d99325ac8d618f1cdf7a3014287c reverted Also building a kernel @ https://git.kernel.org/cgit/linux/kernel/git/joro/iommu.git/commit/?h=iommu-updates-v4.2&id=b63d80d1e01e949dbe469e1d72fc0b7e173dbdd8 right now (b/c I forgot to save it somewhere ...), which is the commit before 5f0a7f7614a9d99325ac8d618f1cdf7a3014287c. I'll add a dmesg of that later as well.
Created attachment 220191 [details] 4.1.0/b63d80d1e01e949dbe469e1d72fc0b7e173dbdd8 dmesg Also removed Nvidia and AMD drivers this time, so less noise.
Created attachment 220421 [details] Possible fix Can you please test whether this patch fixes the problem?
Yep, it's working. Tested on 4.6.2.
(In reply to florian.ziesche+linux from comment #5) > Yep, it's working. Tested on 4.6.2. Thanks, patch is now upstream in Linus' tree and should land in the stable-trees for older kernels soon.
Fixed by a4c34ff1c029, which appeared in v4.7. http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a4c34ff1c029